Title

The system must implement non-executable program stacks. (Cat II impact)

Discussion

A common type of exploit is the stack buffer overflow. An application receives, from an attacker, more data than it is prepared for and stores this information on its stack, writing beyond the space reserved for it. This can be designed to cause execution of the data written on the stack. One mechanism to mitigate this vulnerability is for the system to not allow the execution of instructions in sections of memory identified as part of the stack.

Check Content

Determine if the system implements non-executable program stacks. # kctune | grep -i "executable_stack" | tr '\011' ' ' | tr -s ' ' | \ sed -e 's/^[ \t]*//' | cut -f 2,2 -d " " If the executable_stack tunable is set to 1, this is a finding.

Fix Text

# kctune executable_stack=0 The system will require a restart/reboot for the setting to take effect.

Additional Identifiers

Rule ID: SV-35009r1_rule

Vulnerability ID: V-11999

Group Title: GEN003540

Expert Comments

CCIs tied to check.

Controls tied to check. These are derived from the CCIs shown above.